import numpy as np
import cv2

canvas = np.zeros((120, 340, 3), np.uint8)
# 圆心  60,60  半径50   60,170  60,290
canvas = cv2.circle(canvas, (60, 60), 50, (0, 0, 255), -1)
canvas = cv2.circle(canvas, (170, 60), 50, (0, 255, 255), -1)
canvas = cv2.circle(canvas, (290, 60), 50, (0, 255, 0), -1)
cv2.imshow('红绿灯', canvas)
cv2.waitKey()
cv2.destroyAllWindows()

